What about the good old method of using several BSDFs inside one layer?gmenzel wrote:There is nothing to simply "fix". If you add reflections on top of an already (even diffusely) reflective surface, you get more light reflected than you should. What is needed is a better approach to physically stacked material layers. Something like the coating component, only more capable.
Blending BSDFs can only ever be an approximation, because the blending weights are fixed and independent from the angle of incident light. This approach will unfortunatelly never produce realistic behavior for glossy materials.ababak wrote:What about the good old method of using several BSDFs inside one layer?
It looks like a synthetic and not realistic material, while Maxwell is about realism. Do you have any real world examples that you can't mimic that way?photomg1 wrote:the only way I can correctly mimic the effect shown on the link is to use additive as shown earlier on in this thread with Jason's video link.
https://support.solidangle.com/download ... 000&api=v2
The issue I have described only relates to fresnel in as far as the effect tends to be the most visible at grazing angles, because, for most materials, that's where reflectiveness is the strongest. Look at the examples on page 4 for a direct comparison. If the additive approach to coatings had no side effects, these two images should look identical.photomg1 wrote:In trying to replicate that scene I linked , a coating also does not replicate it gmenzel( used a 75000 nm coating with 1.5 ior force fresnel) . It never gets bright enough at the horizon edge, where as additive matches completely ( 1.5 ior force fresnel ) .
Is it just the bright edge of fresnel you do not like ? or does maxwell still fail the test with the torus? ( is that mxm available)
Thats a bit of an oxymoronic statement.ababak wrote:It looks like a synthetic and not realistic material, while Maxwell is about realism. Do you have any real world examples that you can't mimic that way?photomg1 wrote:the only way I can correctly mimic the effect shown on the link is to use additive as shown earlier on in this thread with Jason's video link.
https://support.solidangle.com/download ... 000&api=v2
Thats the point I was trying to make before though in that coatings don't seem to give the full fresnel effect in maxwell.gmenzel wrote:The issue I have described only relates to fresnel in as far as the effect tends to be the most visible at grazing angles, because, for most materials, that's where reflectiveness is the strongest. Look at the examples on page 4 for a direct comparison. If the additive approach to coatings had no side effects, these two images should look identical.photomg1 wrote:In trying to replicate that scene I linked , a coating also does not replicate it gmenzel( used a 75000 nm coating with 1.5 ior force fresnel) . It never gets bright enough at the horizon edge, where as additive matches completely ( 1.5 ior force fresnel ) .
Is it just the bright edge of fresnel you do not like ? or does maxwell still fail the test with the torus? ( is that mxm available)
Maxwell's own coating component is physically correct in at least the sense that it doesn't cause light amplification. I haven't used the coating component much though, because of its limitations, which make it less useful for my work. But I think it serves as a good baseline when comparing the results of alternative approaches.photomg1 wrote:Thats the point I was trying to make before though in that coatings don't seem to give the full fresnel effect in maxwell.
It only serves as a baseline if it correctly adheres to the correct ior fresnel brightness/reflection amount at glancing angles. This is what I'm throwing into question, hence the scene I was showing as an example to match.gmenzel wrote:Maxwell's own coating component is physically correct in at least the sense that it doesn't cause light amplification. I haven't used the coating component much though, because of its limitations, which make it less useful for my work. But I think it serves as a good baseline when comparing the results of alternative approaches.photomg1 wrote:Thats the point I was trying to make before though in that coatings don't seem to give the full fresnel effect in maxwell.
It might be better to open a new thread specifically for that question. The purpose of this thread here is to address the light amplification problem when using the additive approach to simulate coated materials.photomg1 wrote:It only serves as a baseline if it correctly adheres to the correct ior fresnel brightness/reflection amount at glancing angles. This is what I'm throwing into question, hence the scene I was showing as an example to match.
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